1. Field of the Invention
The present invention relates to an improvement of a water-proof connector and a dummy plug for use in a water-proof connector.
2. Description of the Prior Art
Generally, a multi-terminal water-proof type connector (hereinafter just referred to as a water-proof connector) contains a plurality of individually separated terminal accommodating chambers, wherein dummy plugs are required to shut up unused chambers which are generated due to addition and/or abolition of optional circuits.
FIG. 7 denotes an example of a conventional water-proof connector, in which a female terminal c is firmly fitted into a terminal accommodating chamber b of a connector housing a, and a lead wire d connected to the female terminal c is drawn outward by way of a lead wire through-hole e1 formed in the central portion of a sealing plug e. Stuffed in another terminal accommodating chamber b' is a dummy plug having no through-hole formed therein.
It is necessary to detect whether or not dummy plugs are already stuffed in empty terminal chambers so that there should be no chambers remained unplugged. However, it is not an easy job to detect it from outside due to the fact that each of the dummy plugs e' is inserted rather deep inside the individual terminal accommodating chambers b', and also due to the difference of the respective locations of the dummy plugs in each of the terminal accommodating chambers. In order to complete the detection thereof, there has been provided such a device as disclosed in Japanese Patent Application Laid Open No. 5-3065 and Japanese Utility Model Application Laid Open No. 5-59762, in which a water-proof connector is settled in the main body of the device which is capable of airtightly keeping the inner ambient and provided with pressurized air therein, whereby the existence of stuffed dummy plugs is detected by a change of the inner air pressure. The device as constructed as above, however, is rather cost consuming as it requires precision machinery components such as a pressurizing means, a pressure sensor and so on.
Apart from the above device, there has been provided a connector terminal detecting tool as disclosed in Japanese Patent Publication NO. 2-56786, which can be adopted even for a connector provided with a spacer for terminal double-locking operation normally disposed at a side surface or back surface of the housing, wherein it is detected whether or not empty chambers are stuffed by dummy plugs by bringing a contact switch or a detection pin of the connector terminal detecting tool into contact with the dummy plug and checking the result thereof. However, the reliability of this type of detection is not sufficient due to the above difference of the locations of the individual inserted dummy plugs.